Defence of dissertation in the field of Engineering Physics, Yongping Liao, M.Sc.
Title of the dissertation is "Carbon dioxide-assisted synthesis of single-walled carbon nanotubes and their thin film properties".
Adding a small amount of carbon dioxide can significantly change the growth of single-walled carbon nanotubes.
Single-walled carbon nanotubes, as a tubular structure rolled up from an atomic-thick graphene layer, have found many applications in modern technologies, such as transistor, touch screens and new types of solar cells. By nature, carbon nanotubes display grey or black colors.
This dissertation focuses on the atomic structure control of single-walled carbon nanotubes in the fabrication process, when using carbon monoxide as the carbon source and iron nanoparticles as the catalysts. For the first time, the colorful single-walled carbon nanotube thin films were directly synthesized. The secret is to introduce small amount of carbon dioxide during tube growth. Due to the variation of the atomic structure, the single-walled carbon nanotubes can exhibit different colors. In addition to colors, the conductivity of single-walled carbon nanotube thin films is also found to be enhanced by adding carbon dioxide. This thesis also studies the properties of graphene/single-walled carbon nanotube hybrid thin films. By combining the carbon nanotubes (produced by carbon dioxide assistance) with graphene, the hybrid thin film shows remarkably increased conductivity.
The addition of carbon dioxide opens the way towards the structural-controlled synthesis of single-walled carbon nanotubes, readily allowing the applications in electronics fields.
Opponent: Dr. Juan José Vilatela, IMDEA Materials Institute, Spain
Custos: Professor Esko Kauppinen, Aalto University School of Science, Department of Applied Physics
Contact information: Yongping Liao, Department of Applied Physics, +358504101280, [email protected]
The dissertation is publicly displayed 10 days before the defence at the noticeboard of the School of Science in Konemiehentie 2, Espoo.